setup: drop two vale errors my own callout introduced

`Microsoft.Contractions` fires on "is not" and "it is", and both were in
the sentence I added about the role having no consumer yet. Reworded so
neither appears, and the passive construction goes with them.

The vale job is red on every PR by design -- ci.yml says so, the docs
tree has a standing backlog against these rules -- which is exactly why
"vale is red" was not a safe thing to wave through. Checking per line
rather than per job is what found these.

Verified with the invocation ci.yml uses:
`XDG_DATA_HOME=$PWD/.vale-data vale sync && vale docs/getting-started/setup.md`
-> synced 3 packages, 0 errors, 14 warnings. The 2 errors CI reported at
103:39 and 104:7 are the presence control: same rule, same file, prior
commit.

docs/getting-started/setup.md

@@ -99,9 +99,9 @@ ever authenticated to OpenBao, so treat the block above as derived rather than
 exercised — the grants come from `-output-policy`, not from a swarm that came
 up on them.
 
-⚠️ **The role it creates has nothing to present a certificate for yet.** Minting
-a leaf whose CN is `swarm-controller` is not wired up in any deployment shape;
-until it is, the role is provisioning waiting for a consumer.
+⚠️ **The role it creates has nothing to present a certificate for yet.** No
+deployment shape mints a leaf whose CN reads `swarm-controller`, so until one
+does, the role stays provisioning that waits for a consumer.
 
 **Delete the file once that has run.** The unit skips when it's absent, so a
 host that has finished bootstrapping stops carrying the credential — and the